After reviewing all the clicks on our ads last month and finding some clearly malware generated clicks on our site, I reported it to Google and waiting to hear back. The offending network has blocked out any traffic to our web sites from their network via their firewall. I suggested they turn on valid as well as invalid hits on their firewall to see where this traffic is coming from because we were getting bombed (and paying for) a huge amount of clicks from their network.
After digging deeper into network traffic I am seeing some things that I feel like Google should easily be able to block out as invalid clicks and not charge us for them. For instace I've found the following user agents in the mix:
internal zero-knowledge agent from 71.117.15.41 multiple times on 5/31/2008
VB Project from 66.233.201.171 on 6/1/2008
No user agent from 66.228.208.166 on 6/5/2008
libcurl agent from 69.41.14.151 on 5/28/2008
VB Project from 24.113.5.42 on 5/26/2008
No user agent from 75.146.62.233 on 5/26/2008
No user agent from 75.146.62.233 on 5/22/2008
No user agent from 75.146.62.233 on 5/16/2008
Additionally starting on 4/9/2008 we started to get a number of invalid requests which indicate they come from Google and I am very skeptical that these particualr requests are legitimate based on the analytics. I asked Google to stop sending us these types of referrals and it seems like we didn't get any today - I hope that they are gone for good because I am not sure the following clicks came from actual potential customers -- of note this particular IP: 206.169.110.66 also hit our site numerous times with something called "page_prefetcher".
6/9/2008 17:54 67.183.35.29
6/9/2008 14:26 96.239.200.74
6/9/2008 13:38 12.228.1.96
6/8/2008 20:53 67.228.207.202
6/7/2008 16:22 24.18.87.97
6/7/2008 12:58 67.225.66.92
6/6/2008 14:43 150.70.84.27
6/6/2008 14:07 67.135.34.242
6/6/2008 0:21 24.18.139.13
6/5/2008 17:35 4.179.53.243
6/5/2008 17:35 4.179.53.243
6/5/2008 1:15 66.228.208.166
6/3/2008 21:05 70.58.64.231
6/3/2008 19:31 76.28.185.32
6/3/2008 17:26 167.88.201.100
6/3/2008 10:59 66.235.13.106
6/3/2008 8:13 24.19.32.200
6/3/2008 1:20 75.146.62.233
6/2/2008 20:10 76.28.185.32
6/2/2008 20:02 76.28.185.32
6/2/2008 20:01 76.28.185.32
6/2/2008 17:46 216.128.111.206
6/2/2008 17:45 216.128.111.206
6/2/2008 17:43 216.128.111.206
6/2/2008 17:41 216.128.111.206
6/2/2008 17:40 216.128.111.206
6/2/2008 14:11 24.18.211.183
6/2/2008 10:02 66.224.213.198
6/1/2008 20:38 97.113.16.141
6/1/2008 17:37 66.233.201.171
6/1/2008 16:22 75.146.62.233
6/1/2008 4:54 75.146.62.233
5/31/2008 23:53 75.146.62.233
5/31/2008 20:27 67.182.151.157
5/31/2008 19:32 76.121.171.169
5/31/2008 17:05 71.117.15.41
5/31/2008 17:05 71.117.15.41
5/31/2008 17:05 71.117.15.41
5/31/2008 16:36 71.121.204.110
5/31/2008 15:12 66.147.230.40
5/31/2008 14:56 24.113.130.126
5/31/2008 13:19 71.231.107.142
5/30/2008 19:33 66.228.208.165
5/30/2008 19:33 66.228.208.165
5/30/2008 17:21 63.225.178.179
5/30/2008 15:37 216.128.111.204
5/30/2008 15:25 216.127.48.246
5/30/2008 13:47 216.254.12.195
5/30/2008 8:53 207.66.220.2
5/30/2008 7:45 150.70.84.27
5/30/2008 7:33 150.70.84.27
5/29/2008 20:54 24.16.195.38
5/29/2008 20:43 24.16.195.38
5/29/2008 19:16 66.228.208.165
5/29/2008 19:07 71.231.183.118
5/29/2008 16:12 76.22.29.101
5/29/2008 14:34 69.56.81.124
5/29/2008 12:35 69.56.81.146
5/29/2008 10:44 76.28.187.65
5/29/2008 9:05 216.127.38.230
5/29/2008 7:41 66.243.225.80
5/29/2008 6:47 66.228.208.167
5/29/2008 2:31 207.246.157.67
5/28/2008 18:25 69.41.14.151
5/28/2008 18:25 69.41.14.151
5/28/2008 13:37 66.228.208.166
5/28/2008 10:24 207.178.0.196
5/28/2008 10:18 75.172.16.64
5/28/2008 8:23 207.178.1.65
5/28/2008 8:17 70.193.81.125
5/27/2008 21:07 71.112.253.195
5/27/2008 17:14 38.100.225.210
5/27/2008 14:19 24.19.50.253
5/27/2008 13:25 66.165.27.95
5/27/2008 10:34 207.178.0.196
5/27/2008 10:15 207.178.14.6
5/26/2008 18:49 75.100.185.182
5/26/2008 17:26 71.120.229.172
5/26/2008 17:25 71.212.8.188
5/26/2008 16:58 150.70.84.48
5/26/2008 16:04 207.66.160.1
5/26/2008 16:04 76.121.42.138
5/26/2008 13:57 76.121.230.246
5/26/2008 12:34 69.29.203.249
5/26/2008 12:25 67.40.195.145
5/26/2008 12:25 67.40.195.145
5/26/2008 10:20 24.113.5.42
5/26/2008 10:12 207.178.0.196
5/26/2008 9:14 24.17.71.223
5/26/2008 8:53 24.17.71.223
5/26/2008 7:34 24.17.71.223
5/26/2008 3:47 75.146.62.233
5/25/2008 23:15 67.171.46.218
5/25/2008 20:13 150.70.84.48
5/25/2008 16:11 208.51.49.107
5/24/2008 20:51 24.113.18.222
5/24/2008 20:47 216.127.38.230
5/24/2008 20:46 24.113.18.222
5/24/2008 19:49 216.127.52.10
5/24/2008 19:48 24.113.130.126
5/24/2008 19:09 207.246.140.49
5/24/2008 15:31 207.66.160.61
5/24/2008 14:14 207.178.1.68
5/24/2008 13:22 24.21.113.66
5/24/2008 12:25 150.70.84.27
5/24/2008 12:15 216.127.48.244
5/24/2008 7:30 150.70.84.27
5/24/2008 7:29 207.66.220.2
5/23/2008 16:24 71.35.106.207
5/23/2008 15:26 98.203.214.173
5/23/2008 8:04 207.207.79.115
5/22/2008 14:30 67.168.130.61
5/22/2008 14:14 75.146.62.233
5/22/2008 12:23 24.17.217.160
5/22/2008 12:23 24.17.217.160
5/22/2008 10:08 207.178.14.1
5/21/2008 20:23 24.22.230.114
5/21/2008 15:03 71.164.20.21
5/21/2008 7:56 24.26.58.81
5/20/2008 19:20 65.101.143.10
5/20/2008 16:53 24.19.154.34
5/20/2008 14:29 65.113.243.198
5/20/2008 13:13 65.113.243.198
5/20/2008 11:29 207.66.220.2
5/20/2008 9:22 207.246.152.67
5/20/2008 8:00 207.246.152.70
5/20/2008 5:38 207.246.157.68
5/20/2008 5:23 76.28.190.90
5/20/2008 5:21 207.246.154.133
5/20/2008 3:01 207.178.0.196
5/20/2008 2:07 207.66.220.2
5/20/2008 2:03 216.240.139.9
5/20/2008 0:26 207.178.0.196
5/19/2008 17:06 70.192.106.3
5/19/2008 15:11 98.203.214.173
5/19/2008 15:09 98.203.214.173
5/19/2008 12:53 130.76.32.23
5/19/2008 12:30 71.39.132.114
5/19/2008 11:14 207.178.1.67
5/18/2008 20:24 207.246.157.65
5/18/2008 20:12 207.178.0.196
5/18/2008 19:22 68.178.78.154
5/18/2008 16:24 75.92.161.253
5/18/2008 14:34 216.127.52.12
5/18/2008 12:41 71.35.145.22
5/18/2008 11:45 207.66.220.2
5/18/2008 8:01 71.113.40.8
5/18/2008 7:46 207.178.0.196
5/17/2008 22:13 207.66.220.2
5/17/2008 16:26 207.246.154.132
5/17/2008 7:51 24.16.194.235
5/17/2008 5:51 75.146.62.233
5/16/2008 20:03 75.146.62.233
5/16/2008 15:42 155.70.23.45
5/16/2008 12:12 72.11.71.226
5/16/2008 11:07 207.246.157.69
5/16/2008 10:59 207.246.157.69
5/16/2008 5:56 207.246.140.49
5/15/2008 18:47 207.66.220.2
5/15/2008 12:34 207.178.0.196
5/15/2008 12:08 207.246.152.69
5/15/2008 12:06 207.246.152.69
5/15/2008 11:57 68.165.228.136
5/15/2008 8:08 216.127.43.132
5/15/2008 7:12 207.246.157.68
5/15/2008 7:01 216.127.48.242
5/15/2008 6:57 207.178.1.70
5/15/2008 6:50 67.160.45.57
5/15/2008 5:09 207.178.0.196
5/15/2008 5:03 207.178.57.67
5/14/2008 21:11 24.21.122.134
5/14/2008 10:21 207.178.1.67
5/14/2008 10:17 207.178.1.70
5/14/2008 10:17 207.178.1.67
5/14/2008 10:16 207.178.1.67
5/14/2008 10:15 207.178.1.67
5/14/2008 10:12 207.178.57.69
5/14/2008 6:26 207.66.220.2
5/14/2008 5:07 207.178.0.196
5/14/2008 5:04 216.127.44.11
5/14/2008 4:58 207.246.152.68
5/14/2008 4:47 207.246.157.68
5/14/2008 4:40 207.246.140.50
5/14/2008 1:05 216.127.43.134
5/14/2008 0:55 207.246.157.67
5/13/2008 23:04 216.127.48.241
5/13/2008 22:58 207.178.48.67
5/13/2008 22:55 207.178.1.68
5/13/2008 21:04 207.178.0.196
5/13/2008 20:09 207.246.157.67
5/13/2008 19:56 66.180.82.88
5/13/2008 18:43 216.127.38.228
5/13/2008 17:24 71.121.146.152
5/13/2008 15:31 207.178.0.196
5/13/2008 15:29 216.127.52.10
5/13/2008 15:25 216.127.48.244
5/13/2008 15:23 216.127.48.244
5/13/2008 13:39 207.178.1.68
5/13/2008 13:38 207.178.1.66
5/13/2008 13:36 207.178.26.2
5/13/2008 13:33 216.127.44.12
5/13/2008 13:29 216.127.44.12
5/13/2008 13:25 207.246.157.68
5/13/2008 13:22 207.246.157.68
5/13/2008 12:17 207.178.1.66
5/13/2008 9:52 216.127.52.9
5/13/2008 8:19 207.178.0.196
5/13/2008 8:03 207.178.0.196
5/13/2008 6:06 207.66.160.3
5/13/2008 4:32 216.127.48.242
5/13/2008 3:21 216.127.44.14
5/13/2008 3:20 216.127.44.14
5/13/2008 3:13 207.246.157.65
5/13/2008 3:13 207.246.157.65
5/13/2008 0:29 216.127.44.9
5/13/2008 0:14 216.127.44.14
5/12/2008 18:27 207.246.155.196
5/12/2008 18:27 207.246.155.196
5/12/2008 18:24 207.246.155.196
5/12/2008 18:12 207.178.0.196
5/12/2008 18:09 207.178.0.196
5/12/2008 18:07 207.178.0.196
5/12/2008 17:52 63.226.202.112
5/12/2008 17:40 71.231.209.183
5/12/2008 15:40 32.155.26.91
5/12/2008 13:07 207.178.1.69
5/12/2008 13:03 207.178.1.69
5/12/2008 12:47 216.127.38.228
5/12/2008 12:12 207.246.140.52
5/12/2008 12:06 207.246.140.52
5/12/2008 11:57 216.127.44.13
5/12/2008 10:45 216.127.44.11
5/12/2008 9:55 98.203.133.46
5/12/2008 9:55 98.203.133.46
5/12/2008 9:55 98.203.133.46
5/12/2008 9:55 98.203.133.46
5/12/2008 9:47 98.203.133.46
5/12/2008 9:42 207.178.1.68
5/12/2008 1:18 207.178.0.196
5/12/2008 1:06 207.246.152.66
5/11/2008 21:41 71.231.72.47
5/11/2008 18:35 76.28.152.19
5/11/2008 17:55 67.183.123.209
5/11/2008 17:38 207.246.140.51
5/11/2008 14:57 66.180.82.88
5/11/2008 11:58 66.180.82.88
5/11/2008 9:39 207.178.0.196
5/11/2008 9:00 207.178.0.196
5/11/2008 8:54 216.127.48.241
5/11/2008 8:03 207.178.57.69
5/11/2008 6:37 98.203.133.46
5/11/2008 6:28 98.203.133.46
5/11/2008 6:15 207.178.1.69
5/11/2008 3:05 71.231.133.31
5/11/2008 2:25 207.178.1.67
5/11/2008 2:18 207.246.152.70
5/11/2008 2:10 207.246.140.50
5/11/2008 0:29 71.113.51.111
5/11/2008 0:22 207.178.0.196
5/10/2008 19:45 76.28.190.90
5/10/2008 18:35 207.246.157.69
5/10/2008 18:05 207.246.157.68
5/10/2008 17:56 216.127.48.241
5/10/2008 17:52 216.127.48.241
5/10/2008 16:25 66.180.82.88
5/10/2008 14:26 67.168.174.55
5/10/2008 13:39 216.127.38.230
5/10/2008 13:37 207.246.157.65
5/10/2008 13:37 216.127.38.230
5/10/2008 13:36 216.127.38.230
5/10/2008 12:24 207.178.0.196
5/10/2008 11:08 207.246.157.68
5/10/2008 10:58 207.178.1.69
5/10/2008 10:26 207.178.57.69
5/10/2008 10:13 216.127.52.9
5/10/2008 9:47 207.178.0.196
5/10/2008 9:36 216.127.38.230
5/10/2008 9:28 207.178.14.4
5/10/2008 9:26 207.178.14.4
5/10/2008 8:45 207.66.160.3
5/10/2008 8:42 207.66.160.3
5/10/2008 4:02 216.127.44.14
5/9/2008 20:15 67.160.58.222
5/9/2008 9:13 24.22.210.15
5/9/2008 9:13 24.22.210.15
5/8/2008 21:26 75.146.62.233
5/8/2008 17:15 206.191.173.159
5/8/2008 15:27 75.121.224.62
5/8/2008 11:14 207.178.0.196
5/8/2008 11:14 207.178.0.196
5/8/2008 11:14 207.178.0.196
5/7/2008 19:20 69.10.212.5
5/7/2008 16:48 66.180.82.88
5/7/2008 12:16 66.165.5.154
5/7/2008 11:59 24.18.210.251
5/6/2008 21:30 71.121.134.24
5/6/2008 12:47 207.178.0.196
5/6/2008 11:44 75.216.224.213
5/6/2008 9:30 150.70.84.154
5/6/2008 8:56 66.180.82.88
5/5/2008 15:11 216.240.139.9
5/5/2008 9:07 66.180.82.88
5/5/2008 6:06 24.18.187.97
5/4/2008 12:59 24.19.46.195
5/3/2008 19:13 152.117.241.94
5/3/2008 16:20 71.112.8.239
5/2/2008 14:40 67.170.104.206
5/2/2008 14:21 76.115.181.71
5/2/2008 12:14 66.213.206.2
5/1/2008 13:12 66.150.9.2
5/1/2008 13:11 65.102.63.59
4/30/2008 20:49 207.108.209.249
4/30/2008 19:21 207.200.116.71
4/30/2008 19:21 207.200.116.71
4/30/2008 16:27 208.70.118.237
4/30/2008 12:24 71.188.250.70
4/29/2008 12:55 4.242.9.82
4/29/2008 12:55 4.242.9.82
4/29/2008 11:55 67.170.95.168
4/29/2008 10:06 71.112.244.57
4/29/2008 10:04 71.112.244.57
4/27/2008 10:22 98.225.29.252
4/27/2008 7:31 24.18.228.135
4/26/2008 19:23 71.212.2.103
4/26/2008 19:01 70.125.156.68
4/26/2008 12:03 76.121.14.238
4/25/2008 14:24 146.129.247.2
4/25/2008 10:19 75.165.14.201
4/25/2008 2:55 199.117.2.58
4/24/2008 20:19 207.200.116.6
4/24/2008 20:19 207.200.116.6
4/24/2008 20:15 207.200.116.134
4/24/2008 20:15 207.200.116.134
4/24/2008 20:10 75.121.224.31
4/24/2008 16:07 65.160.238.180
4/24/2008 14:56 67.183.126.104
4/24/2008 14:24 67.183.126.104
4/22/2008 14:13 207.225.242.1
4/22/2008 10:01 64.122.250.13
4/21/2008 17:16 4.242.60.232
4/21/2008 16:50 4.242.60.232
4/21/2008 9:01 76.84.97.87
4/20/2008 19:49 24.18.132.106
4/20/2008 16:31 216.240.139.9
4/20/2008 9:00 24.113.218.28
4/20/2008 8:24 70.109.87.156
4/19/2008 9:29 67.101.1.198
4/19/2008 9:05 66.67.167.138
4/18/2008 12:16 68.55.80.153
4/18/2008 11:02 74.61.14.69
4/18/2008 8:36 216.220.163.131
4/17/2008 14:52 204.11.206.66
4/17/2008 10:54 72.160.81.9
4/17/2008 9:41 67.171.38.15
4/17/2008 7:54 70.145.72.210
4/16/2008 8:35 130.76.32.145
4/16/2008 1:08 76.22.98.254
4/15/2008 20:36 38.103.128.245
4/15/2008 11:33 63.229.10.210
4/15/2008 11:04 64.221.112.226
4/15/2008 8:11 150.70.84.27
4/14/2008 13:31 208.64.242.83
4/14/2008 10:52 38.103.128.245
4/14/2008 8:55 204.246.129.196
4/14/2008 8:17 38.103.128.245
4/14/2008 8:15 38.103.128.245
4/14/2008 8:15 38.103.128.245
4/14/2008 7:03 150.70.84.154
4/13/2008 15:04 4.242.60.93
4/13/2008 15:00 4.242.60.93
4/13/2008 14:35 4.242.60.93
4/13/2008 14:08 71.231.10.128
4/13/2008 14:08 71.231.10.128
4/13/2008 14:08 71.231.10.128
4/12/2008 16:25 75.172.87.114
4/12/2008 15:59 24.145.231.173
4/12/2008 15:26 71.249.87.226
4/12/2008 14:27 69.214.22.116
4/12/2008 12:33 207.43.224.70
4/12/2008 12:33 207.43.224.80
4/12/2008 9:57 150.70.84.27
4/12/2008 9:46 70.145.21.26
4/12/2008 9:28 74.242.96.197
4/12/2008 1:54 216.240.139.9
4/11/2008 23:57 65.101.141.82
4/11/2008 21:31 4.243.49.100
4/11/2008 8:30 67.170.85.124
4/10/2008 14:11 150.70.84.154
4/9/2008 20:26 71.127.254.195
4/9/2008 17:22 198.238.208.2
4/9/2008 15:51 199.233.178.253
4/9/2008 14:54 208.65.83.39
4/9/2008 13:44 67.183.164.154
4/9/2008 12:00 199.147.202.24
4/9/2008 11:49 199.147.202.24
4/9/2008 10:00 150.70.84.27
4/9/2008 8:41 216.20.149.124